Drive-spring fastener



March 21, 1950 F. -FENGLER DRIVE-SPRING FASTENER 'nba April 2s. 194s Patented Mar. 21, 1950 DRIVE-SPRING FASTENER Ferdinand Fengler, Bristol, Conn., assigner to The E. Ingraham Company, Bristol, Conn., a corporation of Connecticut Application April z3, 194s, serial No. 664,371

(c1. sia- 52) 4 Claims.

The present invention relates in general to timepieces and more especially to improved means for securing an element such as a spring to the frame of the timepiece.

Heretofore, the free or outer ends of elements such as the mainsprings and alarm springs of timepieces have been made fast to the frame by fastening-means comprising, almost universally, a separate clamp or a clamp formed integrally on the outer end of the springend secured to one of the pillars of the frame by a rivet or similar fastening-means. This construction is not only relatively expensive but has necessitated that the entire frame be disassembled to replace a broken spring.

An object of the invention is to provide improved means for securing the outer or free end of a spring to the frame of a timepiece.

A further object is to provide spring-fastening means to enable a spring to be disengaged from the frame of a timepiece without disassembling the frame.A

A still further object is to provide an apertured tang on the outer end of a mainspring, the tang being adapted to t over an extremity of one of the pillars of the frame to removably secure the outer end of the spring thereto.

With the above and other objects in View, as will appear to those skilled in the art from the present disclosure, this invention includes all features in the said disclosure which are novel over the prior art and which are not claimed in any separate application.

In the accompanying drawings, in which certain modes of carrying out the present invention are shown for illustrative purposes:

Fig. 1 is a fragmentary plan view of the frame of a timepiece embodying the improved springfastening means of this invention;

Fig. 2 is a front elevation of the frame and spring-fastening means shown in Fig. 1;

Fig. 3 is an enlarged fragmentary plan view of the outer end of the mainspring in the horizontal plane of line 3-3 of Fig. 1; and

Fig. 4 is a fragmentary sectional elevation in the direction of arrows I-I of Fig. 1.

Referring to the drawings which illustrate an exemplary embodiment of the invention, the timepiece-frame is indicated generally at IIl and comprises front and rear movement-plates I I and I2 held in spaced parallel relationship by pillars I3. Mounted between the iront and rear movement-plates is a time-train indicated generally at I4, and an alarm-train indicated generally at I5. The time-train Il comprises a gear-train of conventional construction driven by the force of a wound spiral-mainspring such as shown at I6, the latter being supported on a winding-arbor II which is rotatably mounted at its opposite ends in the front and rear movement-plates. The rear extremity of the winding-arbor I1 is provided with the usual windingkey I8 for manually rotating the arbor I1. The mainspring I6 is secured at its inner end I3 to the windingarbor I'I, the connection between the inner end of the spring and the arbor being the usual type of fastening-means 20. as shown in Fig. 1.

The opposite or outer free end 2| of the mainspring I6 is adapted to be fastened to the frame I0 in a manner such as to enable the outer end 2l of the spring to be readily attached thereto, and removed therefrom with dispatch and without necessitating the disassembly of the entire frame. To this end, the outer extremity 2I of the mainspring I6 is reduced in width, as shown in Fig. 2, the reduced portion constituting a tongue 22 having a radius at its outer end and a longitudinal slot 23. The slot 23 is substantiallv rectangular. its longitudinal axis being eoincident with the longitudinal axis of the tongue 22.

Mounted in the slot 23 is a substantially- T-shaped tang indicated generally at 24; comprising a relatively-thin sheet-metal member having a substantially-rectangular base 25 exceeding in length the length of the slot 23, but substantially equal in thickness to the width thereof (see Fig. 2); and a reach 26, the Width of the latter being substantially less than the width of the slot 23 (see Fig. 3) and offset from and in a plane substantially parallel to the plane through the longitudinal edges of the base 25. as shown in Fig. 4. An aperture 21 is provided in the outer extremity of the reach 23. The inner end of the reach 26 is joined integrally to the base 25 bv the stepped substantially-sanare shoulders 28. the distance between the respective shoulders being substantially equal to the width of the slot 23 in the outer end of the spring.

The tang is adapted to be inserted into the slot 23 reach-end first and to be thrust forwardly therein until the shoulders 28 engage in the corresponding edges of the slot 23. It will be noted that the original height of each shoulder as indicated by broken lines in Fig. 3, exceeds the thickness of the tongue-portion 22 oi.' the spring 2I. In accordance with this construction, the tang may be secured in the slot 23 of the tongue 22 by swaging or peening over the upper edges 0f the shoulders 23, to form beads or ilanges 29 overlying the adjacent face of the tongue 22 which, in conjunction with the extremities 30 of the base 25, overlying the opposite face of the tongue 22 serve to firmly secure the tang in the slot 23 in the outer end of the spring.

As shown in the drawings, the Outer end oi' the spring 2| is adapted to be fastened to the frame l0 by engaging the apertured tang 26 over the upwardly-extending threaded extremity 3l of one of the pillars I 3 of the frame, and to be se- The invention may be carried out in other specie ways than those herein set forth without departing from the spirit and essential characteristics of the invention, and the present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.

I claim:

1. In a timepiece having a frame comprising front and rear movement-plates, pillars to support said plates in spaced parallel relationship, a gear-train, a spring for driving said gear-train said spring having an aperture in its outer end, a spring-winding arbor and means to secure the inner end of said spring to said arbor; of means to removably secure the outer end of said spring to said frame comprising an apertured tang secured permanently in the aperture in the outer end of said spring in a plane substantially at right angles to the plane of the outer end of said Spring and constructed and arranged to cooperatively engage a pillar of said frame.

2. In a time piece having a frame comprising the outer end of said spring, and an apertured m reach, said apertured reach lying in a plane sub- 4 stantially at right angles to the plane of the outer end of said spring and constructed and arranged to cooperatively engage an extremity oi.' a pillar of said frame.

3. In a timepiece having a frame comprising front and rear movement-plates, pillars to support said plates in spaced parallel relationship, a gear-train, a spring for driving said gear-train said spring having an aperture in its outer end, a spring-winding arbor and means to secure the inner end of said spring to said arbor; of means to removably secure the-outer end of said spring to said frame comprising a tang having a baseportion secured permanently in the aperture in the outer end oi said spring, and an apertured reach, said reach being offset from said base and lying in a plane substantially at right angles to the plane of the outer end of said spring so as to make face-to-face contact with the rear face of the rear movement-plate the aperture oi' said reach being adapted to fit over an extremity o! a pillar of said frame.

4. In a timepiece having a frame comprising front and rear movement-plates, pillars to support said plates in spaced parallel relationship, a time-train, a mainspring for driving said timetrain said mainspring having an aperture in its outer end, a mainspring-winding arbor and means to secure the inner end of said mainspring to said arbor; of means to removably secure the outer end of said spring to said frame comprising a tang having a base-portion swaged in the aperture in the outer end oi said mainspring and an apertured reach, said apertured reach lying in a plane substantially at right angles to the plane of the outer end of said spring and constructed and arranged to fit over an extremity of a pillar of said frame, and a member to removably secure said tang to the extremity of said pillar.

FERDINAND FENGLER.

REFERENCES CITED The following references are of record in the file 4of this patent:

UNITED STATES PATENTS Number Name Date 1,086,719 Kern Feb. 10, 1914 1,520,866 Hodge Dec. 30, 1924 FOREIGN PATENTS Number Country Date 3,144 Great Britain Nov. 22, 1862 257,544 Italy Mar. B, 1928 422,303 Germany Nov. 30, 1925 

